China and the US have chance to rebuild trust: Kevin Rudd

CHINA is ill-prepared for the escalating tensions between North Korea and South Korea, former prime minister Kevin Rudd has warned.

But the former diplomat and expert on China said the worrying developments on the Korean peninsula could help bring China and the United States to the negotiating table.

During a speech in Washington this week Mr Rudd warned the "strategic trust deficit" between the US and China was widening.

He argued this gulf made the task of dealing with tensions in the Asia region "increasingly problematic".

A "unique window" existed for the countries to begin building trust, he said, although the US would need to take the lead.

He said the tensions between North and South Korea meant the US-China relationship needed to improve "sooner rather than later" if all-out war was to be avoided.

"Particularly given the unpredictability and political inexperience of Kim Jong-un, the domestic political pressure on newly elected President Park in South Korea to respond in kind to any fresh military provocation from the North, and the absence of a Chinese Plan B if hostilities were to erupt," Mr Rudd told the Carnegie Endowment for International Peace.

His speech came as North Korea continued ratcheting up its threats against South Korea and the US.

There were reports on Thursday Kim Jong-un had given the green light for his army to strike US bases in the region.

Yonhap news agency was reporting North Korea had moved an intermediate-range missile to its east coast in a display of military power.

It had not been confirmed whether the missile was carrying a warhead, but multiple sources told Yonhap Pyongyang was likely to fire it off around April 15, when North Koreans celebrate the birthday of its founder Kim Il-sung.

The alleged action by the North prompted the US to begin moving its advanced missile defence system to its base on the Pacific Ocean island of Guam - two years ahead of schedule.

Pentagon officials told The New York Times the "precautionary move" would happen in the next few weeks.

The New York Times was also reporting North Korea had blocked South Koreans from crossing the border to enter a jointly operated industrial park.

Mr Rudd said North Korea's increasingly aggressive language, coupled with its arsenal of nuclear weapons, meant the rest of the world no longer regarded it as "simply a theoretical threat".

In an interview on CNN after his speech, Mr Rudd said there was a "full blown debate" happening in China about its policy on North Korea.

He said a number of factors was forcing the world's biggest nation, a traditional supporter of North Korea, to reassess its position.

Chief among those was a desire to be taken seriously on the world stage. Mr Rudd said China's credibility was at stake without a change of course, and that this created an opportunity for a strategic dialogue with the US.

"Number one is that North Korea's nuclear weapons program is causing US allies in the region, not just South Korea and the United States but also Japan and others to increase their ballistic missile defence cooperation to protect against any future North Korean attack. Of course that has implications for broader Chinese security interests in East Asia," he said.

"Number two is the Chinese are deeply concerned that if there is a provocation from the North ... that the probability of a retaliatory action by the South Korean government is now very high and the prospects of escalation are large and there's no real Chinese plan B for that."

"The final point which I think we should all bear in mind is being linked to North Korea frankly doesn't do your global reputation a whole lot of good in the foreign policy stakes. That's what is driving, I think, a Chinese rethink as we speak."

Mr Rudd acknowledged China had made several attempts to rein-in North Korea's behaviour.